Ed Miliband had to write an optimistic manifesto. He didn't have to write an illiterate one

Manifesto is an odd word. It's derived from manifest, meaning clear or obvious; not meaning a ludicrously optimistic wish-list, designed to make you vote for the manifesto's author.

Even at the best of times, manifestos are necessarily vague, nebulous documents. This is not the best of times; and, to be fair to Ed Miliband, the poor man entrusted with writing Labour's manifesto, he had an impossible job.

How do you promise the earth – which manifestos are bound to promise – when there's nothing in the kitty? You can't admit you're going to cut anything – although whoever wins in three weeks will have to cut like crazy and put up with being the most unpopular government in 30 years. And you can't commit to big spending increases, because we all know the money isn't there.

And so Miliband had to go for the familiar platitudes: "It is our belief that it is active, reforming government, not absent government, that helps make people powerful"; "Labour believes we must not put the recovery at risk by reckless cuts to public spending this year."

But there's no reason why Miliband, educated at Oxford and the London School of Economics, had to write all those platitudes in such terrible English. He can't tell the difference between "principle" and "principal" ("Our principle opponents, the Conservatives") – a classic test of literacy, because a computer spell-check will miss an incorrect use of either word.

He uses clumsy English to pass off failures as successes: "Unemployment has, so far, risen by over 500,000 less than people expected this time last year" – not the same as saying unemployment has fallen by half a million, but that's the impression he's trying to give.

He uses overblown words to disguise nasty realities: "We believe it is right that those with the broadest shoulders bear the greatest burden of paying down the deficit." Ah, so taxes are going up.

The slapdash prose just goes on and on. Random capital letters and past participle overload, combined with severely rationed commas: "Housing Benefit will be reformed"; "We will provide homeless 16 and 17 year olds with Foyer-based supported accommodation".

The old, familiar educationese: "We are introducing specialist teachers to achieve a similar step-change in Maths"; "Secondary schools: excellence for all, personal to each."

Random use of hyphens: "greater use of tele-care and personal nursing." And then just straightforward illiteracy: "The waiting-time guarantee will ensure that treatment begins within 18 weeks of seeing your GP, or the NHS will find you to go private."

We all know times are tough but, as the patient said to the doctor with the grim diagnosis, "Just give it to me straight, Dr Miliband."